DESCRIPTION: (Applicant's Abstract) HIV/AIDS among injecting drug users (IDUs) is a major health problem. A variety of studies have found that, among IDUs, women who have sex with women (WSWs) and/or women who report that they are lesbian or bisexual are particularly likely to be or become infected with HIV. Since woman-with-woman sex seems to be much less risky than heterosexual sex, this finding is puzzling. The public health importance of this finding is increased by previous research by this team (Friedman et al 1995) that show that, in cities where IDUs have relatively low HIV prevalence (< 8%), WSW IDUs have a multivariate risk ratio of seroconverting that is approximately four times as great as for other IDUs. Thus, WSW IDUs may serve as an early transmission bridge for HIV spread to other IDUs. In high-prevalence cities, WSW IDUs also appear to be more likely to be infected; and are more likely to engage in a number of risk behaviors than other IDUs. Also, there is considerable evidence that there are large numbers of WSW IDUs. Estimates of the proportion of women IDUs who have had sex with women range between 10% and 50%, with 20% - 30% probably representing the best current estimate after taking account under-reporting of this stigmatized behavior. Little, however, is known about WSW IDUs. There have been no ethnographic studies of this group (of the kind that allowed effective HIV prevention in the NIDA-funded outreach projects). Behavioral and epidemiologic reports have derived from larger studies that primarily collected data on "heterosexual" IDUs. Thus, an ethnographic study is needed--and will be conducted--in order to develop a detailed understanding of WSW IDUs' social contexts and behaviors. Ethnographic methods will 1. develop a grounded description of a variety of WSW IDU subgroups and the times and places where they can be found (and recruited); 2 describe drug- and sexual risk behaviors and risk networks of WSW IDUs from different subgroups; and 3. describe the lives and social environments of WSW IDUs of various subgroups. From these descriptions, grounded hypotheses will be developed about why WSW IDUs are at high risk for HIV infection and how to reduce HIV transmission among them. 4. A questionnaire and a sampling strategy suitable for use in research to test hypotheses about HIV epidemiology and prevention among WSW IDUs will be developed and field-tested. This study will lay a necessary basis for research and interventions needed to prevent further spread of HIV to and from WSW IDUs.